Dear Readers: I have two issues in nonparametric statistical analysis that i need help: First, does R have a package that can implement the multimodality test, e.g., the Silverman test, DIP test, MAP test or Runt test. I have seen an earlier thread (sometime in 2003) where someone was trying to write a code for the Silverman test of multimodality. Is there any other tests that can enable me to know how many modes are in a distribution? Second, i would like to test whether two distributions are equal. Does R have a package than can implement the Li (1996) test of the equality of two distributions? Is there any other test i can use rather than the Li test? Thank you in advance for your help. Amin Mugera Graduate Student AgEcon Dept. Kansas State University
the diptest package, perhaps? url: www.econ.uiuc.edu/~roger Roger Koenker email rkoenker at uiuc.edu Department of Economics vox: 217-333-4558 University of Illinois fax: 217-244-6678 Champaign, IL 61820 On Sep 9, 2008, at 11:23 AM, Amin W. Mugera wrote:> > Dear Readers: > > I have two issues in nonparametric statistical analysis that i need > help: > > First, does R have a package that can implement the multimodality > test, > e.g., the Silverman test, DIP test, MAP test or Runt test. I have seen > an earlier thread (sometime in 2003) where someone was trying to write > a code for the Silverman test of multimodality. Is there any other > tests that can enable me to know how many modes are in a distribution? > > Second, i would like to test whether two distributions are equal. > Does R > have a package than can implement the Li (1996) test of the equality > of two distributions? Is there any other test i can use rather than > the > Li test? > > Thank you in advance for your help. > > Amin Mugera > Graduate Student > AgEcon Dept. Kansas State University > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
Hi Amin,>> First, does R have a package that can implement the multimodality test, >> e.g., the Silverman test, DIP test, MAP test or Runt test.Jeremy Tantrum (a Ph.D. student of Werner Steutzle's, c. 2003/04) did some work on this. There is some useful code on Steutzle's website: http://www.stat.washington.edu/wxs/Stat593-s03/Code/jeremy-unimodality.R I used it last year when I was trying to solve the problem of how best to compare lots of density curves (age distributions of 3 spp. of tree euphorbias from about very different 35 sites). In particular I had to ensure that I wasn't creating spurious bimodality at a particular age range when combining sites. You might find it useful. Feel free to contact me off list if the code has gone, as I think I still have it (somewhere). Regards, Mark. Amin W. Mugera wrote:> > > Dear Readers: > > I have two issues in nonparametric statistical analysis that i need > help: > > First, does R have a package that can implement the multimodality test, > e.g., the Silverman test, DIP test, MAP test or Runt test. I have seen > an earlier thread (sometime in 2003) where someone was trying to write > a code for the Silverman test of multimodality. Is there any other > tests that can enable me to know how many modes are in a distribution? > > Second, i would like to test whether two distributions are equal. Does R > have a package than can implement the Li (1996) test of the equality > of two distributions? Is there any other test i can use rather than the > Li test? > > Thank you in advance for your help. > > Amin Mugera > Graduate Student > AgEcon Dept. Kansas State University > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > >-- View this message in context: http://www.nabble.com/Modality-Test-tp19396085p19400095.html Sent from the R help mailing list archive at Nabble.com.
Hi Amin, And I have just remembered that there is a function called curveRep in Frank Harrell's Hmisc package that might be useful, even if not quite in the channel of your enquiry. curveRep was added to the package after my struggles, so I never used it and so don't know how well it performs (quite well, I would think). Regards, Mark. Amin W. Mugera wrote:> > > Dear Readers: > > I have two issues in nonparametric statistical analysis that i need > help: > > First, does R have a package that can implement the multimodality test, > e.g., the Silverman test, DIP test, MAP test or Runt test. I have seen > an earlier thread (sometime in 2003) where someone was trying to write > a code for the Silverman test of multimodality. Is there any other > tests that can enable me to know how many modes are in a distribution? > > Second, i would like to test whether two distributions are equal. Does R > have a package than can implement the Li (1996) test of the equality > of two distributions? Is there any other test i can use rather than the > Li test? > > Thank you in advance for your help. > > Amin Mugera > Graduate Student > AgEcon Dept. Kansas State University > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > >-- View this message in context: http://www.nabble.com/Modality-Test-tp19396085p19400426.html Sent from the R help mailing list archive at Nabble.com.